This invention relates to methods and apparatus for mounting and demounting tires, particularly large tires as are typically employed with oversized vehicles as off the road vehicles.
While automobiles have utilized tires mounted on one-piece wheels having drop centers for decades, little use of such wheels has been made in connection with larger vehicles requiring tires significantly larger than those used on automobiles. Rather, where large tires have been required, conventionally so-called "split-rim" type wheels have been utilized.
The latter type of wheel has been favored over the former for mounting large tires because due to the stiffness of large tires, it has been virtually impossible to mount the same on one piece wheels. However, split-rim type wheels are not without their disadvantages for they are formed of multiple components including two wheel halves, a locking ring and one or more sealing gaskets at the very least. And, it is necessary to disassemble a split-rim type wheel for the purpose of either mounting a tire thereon or removing a tire therefrom. The seals or gaskets require replacement and a certain degree of hazard is present when the locking ring is applied to the wheel or removed therefrom.
In order to avoid these disadvantages, and attain the advantages normally associated with one-piece type wheels in connection with larger tires, there have been proposed methods and apparatus for mounting and demounting large tires on one-piece wheels. Such proposals are exemplified by, for example, the following U.S. Pat. No.: 3,489,198 issued Jan. 13, 1970 to Malinski; U.S. Pat. No. 3,612,140 issued Oct. 12, 1971 to Malinski; U.S. Pat. No. 4,014,375 issued Mar. 29, 1977 to Malinski et al; and U.S. Pat. No. 4,031,941 issued Feb. 17, 1976, also to Malinski et al.
Apparatus stated to be manufactured under one or more of the above patents is commercially available and has made it possible to mount large tires, such as those used on off the road vehicles, on one-piece rims. However, the apparatus utilized is quite complex utilizing numerous pushing devices for distorting a tire during the mounting or demounting process as well as rotating bead deflector mechanisms. The methods by which the tires are mounted or demounted are relatively complex in terms of the number of steps which must be performed.
And the locale in which the equipment is used, of necessity, cannot be utilized for non-mounting or demounting purposes by reason of the construction of the equipment preventing such use.